Expansion joint device



Jan. 10, 1961 M. F. MAU'DE EXPANSION JOINT DEVICE Filed Aug. 14, 1957 INVENTOR. MacHAEL F. MAUDE ATTORNEY United States Patent-f) 2,967,467 EXPANSION JOINT DEVICE Michael F. Maude, 4015 W. Patterson Ave., Chicago 41,111.

Filed Aug. 14, 1957, Ser. No. clams ,6 C a ms 1- 2 8) This invention relates in general'to expansion joints and in particular to a temporary expansion joint-removable after pouring of concrete or the like.

It is standard practice in concrete construction of roads, driveways, floor slabs, side walks and the like to use expansion joints to provide for expansion and contraction due to temperature changes.

Many different forms of expansion joints are used, all with varying degrees of success. One of the greatest difiiculties and inconveniences encountered with expansion joints is that they usually cannot be preset for the exact height needed and consequently must be trimmed down after the concrete has set. This procedure is time consuming and costly and cannot be done too neatly.

It is therefore the primary object of my invention to provide a preformed expansion joint with an impermeable topping of a foamed polystyrene such as Styrofoam or similar material so applied to the base of the expansion joint that the topping may be readily peeled OK after the concrete has set and the resultant groove quickly and easily filled with any suitable compound or mastic, preferably by pouring.

Other objects and advantages, as well as the construction and manner of use of my invention will be readily apparent by reference to the following specification in connection with the accompanying drawing in which:

Fig. 1 is a fragmentary cross-sectional view through a joint in which my invention is employed.

Fig. 2 is a similar view of the joint with the topping removed and the resultant groove remaining.

Fig. 3 is a similar view with the groove filled with an additional supply of mastic to level the expansion joint with the adjacent concrete.

Fig. 4 is an isometric view of the expansion joint in use with the Styrofoam top being peeled off.

Referring now to the drawing by numerals of reference, 1 designates concrete slabs which may be a roadway, driveway, sidewalk, fioor or any other surface in which expansion joints are needed.

Before pouring the concrete an expansion joint or base member 2 of any suitable material but preferably having elastic characteristics is set with the forms for the concrete or before pouring an adjacent slab.

This expansion joint is provided with a topping 3 of Styrofoam or a similar and suitable material which is applied to the expansion joint by any suitable adhesive.

Styrofoam, a trade name for a foamed polystyrene material, has been found to be a very adequate material in that it has ample body to withstand the pressure of the concrete, yet it is light and relatively inexpensive, making it ideal for such use. Its brittleness makes it easy to remove. Also, a foamed polystyrene material such as Styrofoam is impermeable to moisture and contracts or expands a relatively small amount. Further, it has a high overall compression factor to withstand heavy dispersed loads such as the pressure of adjacent slab surfaces or the pressure of a material leveling implement used in road building. n the other hand a concentrated ice load such as rocks or gravel used to form the slabcan;

be forced into the foamed polystyrene and removedw'hen the topping member is removed.

After the expansion joint is properly positioned and the concrete has been poured and set, theStyrofoam topping is easily removed as shown in Fig. 4, leaving the groove 4 as indicated in Fig. 2.

' The resultant groove 4 may be filled by hottar or asphalt, mastic 'or any suitable compound 5 to the-level of the adjacent concrete slabs as shown in Fig. 3.

' Removal of the Styrofoam may be accomplished any suitable tool of proper width which may be pushed along the groove between the Styrofoam topping :3 and the mastic baseZ.

From the foregoing it will be'seen that I have provided a very simple but eflt'ective expansion joint in which a topping member will give suflicient body while concrete is being poured and which can be quickly and easily stripped oif after the concrete has set to allow for filling of the resultant groove with a suitable mastic or filling to a desired level.

Obviously, changes in form, proportion or minor de tails of construction may be resorted to without departing from the spirit of my invention and I reserve all rights to such changes as come within the scope of these specifications and the claims which follow.

What I claim as new and desire to secure by Letters Patent is:

1. In an expansion joint device in combination with spaced adjacent slabs formed by pouring concrete, said device comprising a base member of a width corresponding to the desired space between the vertical edge surfaces of the adjacent concrete slabs and a height less than that of the slabs, a removable topping member on the base member, said topping member being fabricated of a foamed polystyrene material whereby said topping member is relatively easily crashed when subjected to a concentrated load such as an aggregate in a concrete mixture so that as material leveling implements screed material over said joint member said topping member serves to receive said aggregate rather than deflecting said implements from their normal path, and means for securing said topping member to said base member.

2. The method of forming an expansion joint between slabs which consists of applying a compressible base member of less height than the thickness of the desired slabs in the area of the slabs to be formed, securing a foamed polystyrene topping member to the top of the base member to a height substantially flush with the surface level of the desired slabs, placing a slab on each side of and in contact with the base member and topping member combination to a level substantially flush with the upper surface of said topping member, removing said topping member after the slabs have hardened to form a groove therebetween and filing said groove with base member and topping member combination to ,a

level substantially flush with the upper surface of said topping member, removing said topping member after the slabs have hardened to form a groove therebetween, and filling said groove with ahot joint mastic to the surface level of said slabs, whereby any particles of Styrofoam left in the groove after removal of the topping member will be reduced by the hot joint mastic from a brittle Patented Jan. 10, v

state and reduced in volume with little or no efiect on the sealing characteristics of the hot joint mastic.

4. The method of forming an expansion joint between slabs which consists of applying a compressible base member adjacent a vertical edge surface of a formed slab, said compressible base member being of less height than the thickness of said slab, securing a foamed polystyrene topping member to the top of the base member to a height substantially flush with the surface level of the formed slab, forming a slab in contact with the compressible base member and topping member combination to a level substantially flush with the upper surface of said topping member, removing said topping member after the slab has hardened to form a groove between the slabs and filling said groove with a joint mastic to the surface level of said slabs.

5. The method as specified in claim 4, said mastic being a hot joint mastic whereby any particles of Styrofoam left in the groove after removal of the topping member will be reduced by the hot joint mastic from a brittle state and reduced in volume with little or no effect on the sealing characteristics of the hot joint mastic.

6. An expansion joint device between vertical edge surfaces of horizontally adjacent slabs, said device comprising the combination of a topping member formed of foamed polystyrene material, a compressible base member disposed between the horizontally adjacent slabs and below the upper surfaces of said slabs, said topping member being disposed above and secured to the compressible base member and having its upper surface substantially flush with the upper surfaces of said slabs to permit removal of said topping member and filling of the groove,

formed by said removal, with a joint mastic.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Engineering Properties and Applications of Plastics, G. F. Kinney, pub. by John Wiley and Sons, Inc., N.Y., 1957, pp. 44-45. 

